Ap1’s would be good

500 pounds is the range of a 2-3 year old set of irons. You may want to start with finding some large golf retailers. They generally take trade-ins While I dearly would like to recommend a Titleist iron, even AP1’s maybe hard to come by at your price. There are multiple versions (2010, 2012, 2014, 2016, and 2018) so some of the early versions may be available in that range. There are other brands, like cobra that depreciate more that could make a good starting point. You’ll need to work with someone at the store that will also find not just price but an appropriate product for your skill level. Forged muscle back or cavity backs won’t be as easily to learn than a game improvement model.

I'd recommend used AP1s and then as you get more serious into the game, save up and get fitted with a local golf professional.