Welcome!
Another vote for the PC Engine Duo-R or RX. Should be able to find one for around $200 shipped on eBay and they are fairly reliable. The black Duos (US Turbo Duo and JP PC Engine Duo) are notorious for cap and other audio issues, but some people have had no problems with them.
With a region mod (to play US hucards) and an Arcade Card Duo or Pro (Duo card is cheaper) you've got access to basically every TG/PCE game ever, except for the half-dozen SuperGrafx games, and you're not missing much.
And yes, people ARE out of their minds with the US prices, but as long as others are paying the prices will remain high. With a region-modded Duo-R you've got access to either US or JP cards, many JP games are much cheaper than their US counterparts and you have the option as long as they are English friendly.