Launching its general election manifesto, party leader Leanne Wood said she wanted an "end to austerity".
Ms Wood said the four Westminster leaders offered "nothing more than further swingeing cuts" to voters.
Plaid says it will negotiate jointly with the SNP and the Greens if there is a hung parliament.
Plaid Cymru wants the devolved Welsh government funded to the same level per head of population as the Scottish government - which it says amounts to £1.2bn extra a year.
At the party's launch event in Bangor, Ms Leanne Wood accused the UK parties of giving "no commitment to securing an economic recovery for all".
Plaid wants to restore the 50p income tax rate for earnings above £150,000, increase National Insurance contributions for higher earners and put a tax on sugary drinks.
Ms Wood also pledged to create up to 50,000 jobs by awarding more public contracts to Welsh firms.
Main pledges
Plaid's manifesto contains plenty of familiar territory but there's no mention of the £1.2bn which is repeatedly referred to by Leanne Wood as the extra funding Wales needs to achieve parity with Scotland.
It talks about the creation of an independent commission to resolve funding issues in future.
Elsewhere, there are plans to reintroduce the 50p top rate of income tax.
Independence is not mentioned until page 36 out of a 64 page document, and then only briefly.
Plaid Cymru has promised more cash for Welsh public services, an extra 1,000 medical jobs and to scrap taxes for 70,000 small businesses.