How much cost would artificial pollination add to common products (fruits etc.)?
The cost would increase; either because pollination services are not provided and the supply is decreased; or because the cost to producers goes up as they must pay for artificial pollination. See the extremely detailed analysis in Winfree et al.

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I imagine what you're actually asking for is a $ figure "per apple". This depends on the location, crop, market, etc., but just for a ballpark, if I'm reading the supplementary tables in Allsop et al correctly, the replacement value of insect pollination to apples in the Western Cape of South Africa would represent a 6%-25% increase in production cost (and, if the producers pass that along to the consumers, an equal increase in the cost to consumer).


 Allsopp MH, de Lange WJ, Veldtman R. 2008. Valuing insect pollination services with cost of replacement. PLoS ONE 3: e3128–e3128.
 Winfree, Gross, Kremen. 2011. Valuing pollination services to agriculture. Ecol Econ 71: 9–9. [behind paywall, but posted free here]