The first thing that pops into my mind would be a pre-WW II Stanley #4 or #4 1/2. You may get lucky and find one on eBay for $50 or so – but you should also look around at local yard sales, your local Craigslist, etc. You can fix those up very easily and made a good user plane out of a surprisingly dingy tool purchase.
Otherwise, you could buy an iron (or a cap iron and iron set if you like Krenov style planes) and make your own. That may be an enjoyable way to get into it since you already have some power tools to assist you in the fabrication of the plane body. There’s plenty of online resources to show you how…youtube is awash with “how to” videos.