<prompt> Human: A bit of backstory: My fiance 31F and I 31M are getting married in a few weeks after 2.5yrs, and once we get back from our honeymoon we plan to start looking in earnest for a house together. We have a bit saved up and some idea of where we would likecan afford, which is mainly in the western, cheaper side of town. We also plan to have kids in the next few years. My fiances parents we all get along fine btw live in the much more expensive east, a fair drive for us at present. They are really keen to be closer to their potential grandchildren, and would love for us to buy in the east, but this is pretty much out of the question for us with house prices anywhere there. They are currently starting a massive building project constructing several units on some land they bought, with no clear date on when it will be completed. They plan to live in one of the units and sell the other two. They have now advised us to hold off buying a house, as once they have completed their project they plan to look at buying some more land in the east, subdividing, and building two more houses. Their idea is to sell us one of those houses at cost building and land. This is obviously an amazing and generous offer, and a better bargain than we could ever hope to achieve otherwise, however I have significant reservations about it.1. There are too many variables. Who knows how long their current project will take to complete or what complications may arise, and how much they will make from it? Or what they will find if anything thats suitable to buy afterwards? Who knows what the housing market will do in several years time?2. This doesnt fit with our timeframe. Realistically we will be waiting at least several years for this to happen. First they have to complete their current project which they are doing themselves, then they have to sell, then they have to find and buy new land, potentially demolish, plan, subdivide, build. All that time we will still be renting and paying someone elses mortgage. If we have kids in that time we have to move house when they are very young which we wanted to avoid. Our previous plan was to be in our own house by the end of the year.3. After designing and building the house they will retain some emotional ownership of it. I fear that even if they sell us the house they will still be emotionally invested in it. What if we want to Knock down a wall? Re-paint? demolish the whole thing? Sell? Even if they tell us we are free to do whatever, I worry that we will feel obliged to include them, and it will affect our freedom. 4. As well as having to wait several more years before getting into our own home, we will have less of a choice about it. Im sure they would include us heavily in the planning and building phase, but it will still not be the same as us shopping around, falling in love with, and choosing a place that we feel meets our needs perfectly. Its also quite likely that a place in the east will have very limited land space, which isnt ideal for me. 5. What if something goes wrong. It is an overly generous offer which I worry may always hang over us, and probably me in particular. I dont like to think of anything going wrong in the relationships between us, but if it did then I feel this sort of arrangement adds a huge layer of complication which we are better off without. It seems like one of those situations we could look back on in 10 years time and regret ever getting ourselves into.My fiance shares some of these reservations but perhaps not to the same extent as me. My main questions are: am I being unreasonable about this? Has anyone else gone through similar arrangements? Most importantly, if we decide to decline this offer, what is the best way to do it without giving offence or seeming ungrateful?TL:DR: My fiances family has made us an overly generous offer which I worry may affect our freedom of choice and complicate things. Were not sure whether to take it or how to decline without giving offence or seeming ungrateful.  <response>: If your fiancées parents arent professional home builders, selling at cost may not be an incredible deal. In fact, it might be much higher than market value. Typically when a consumer builds their own house from the ground up, they pay more. A pro cuts corners where it makes financial sense to and builds pretty good stuff cheaply to appeal to a wide range of people. They also have good connections to get materials cheaply, buy in bulk, know cheap contractors to take care of certain aspects, get things done quickly so not running up property tax bills waiting to build and sell, etc. Its actually hard to know what kind of deal youll be getting unless we get more information. Im not saying it will be impossible to profit on this deal, but its by no means guaranteed.That aside, it sounds like its not worth waiting for all the reasons you listed in the OP. If the deal turns out to be great, you could probably move there when its ready and reconsider. 