There are many credit card deals (especially Visa/Amex Plat level etc) where Priority Pass is supplied for free. However in fact it is only a standard membership plan cost of Priority Pass which is waived (cost around $/EUR 100 otherwise), you still have to pay for each visit ($26 or $27 currently).
Priority Pass also has advanced membership levels where a certain amount of visits or even all visits are covered withing annual cost, but I haven't seen (yet) those plans are supplied for free with credit card deals. Also those credit cards are usually $100+ annual fee depending of your country and bank, although they usually come with a decent travel insurance package which partly of fully offsets the cost (if you travel a lot).
p.s. most of Priority Pass accessable lounges are very basic.