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.

The Scotland winger, 26, suffered the injury in Saturday's 1-0 win at QPR.
Bruce said Snodgrass, who joined Hull in a £6m deal from relegated Norwich this summer, would be missing "for the best part of the season".
Snodgrass was due to see a specialist on Wednesday to undergo surgery.
The player tweeted: "Gutted ....!!! But I will work as hard as I can to come back fitter and stronger."
"We've lost Robert Snodgrass and the diagnosis is he'll be gone for six months which is a big blow to us," Bruce told reporters at Humberside Airport before flying to Belgium for Thursday's Europa League tie with Lokeren
"We spent a lot of money adding to our midfield area and now we've lost Snodgrass for the best part of the season. It's a tragedy for him and for us.
"It's a huge blow. He was brought in to bring that little bit of quality to the midfield area."
Bruce added that he would seek to sign a replacement for Snodgrass before the end of the transfer window.
Snodgrass scored seven goals in 34 appearances last season as the Canaries were relegated from the Premier League.
The player will also miss Scotland's four opening European Championship qualifiers, as well as a friendly against England in November.
"Robert has given everything to become the influential player he has," said Scotland manager Gordon Strachan. "He is a popular guy around the squad, has a first-class attitude and a work-rate that has taken him to the level he has attained.
"It's a shame that this terrible injury has occurred at the start of a new season, with a new club and a new qualifying campaign to look forward to but the best players overcome such adversity in the long run and I have no doubts Robert will do just that."

The former London Irish man, 29, who can play in the second or back row, was injured in Friday's loss at Newcastle.
"He really hurt his neck and he has got pins and needles in his arms and through his hands," director of rugby Todd Blackadder told BBC Points West.
"So he could be out for a little while yet but it's hopefully not too serious. But to lose a big boy like that is an opportunity for someone else."
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.
[NEXT_CONCEPT]
Hull midfielder Robert Snodgrass will be out for up to six months with a dislocated kneecap, manager Steve Bruce has confirmed.
[NEXT_CONCEPT]
Bath forward Matt Garvey is to have surgery after sustaining a neck injury.