See this thread from about 8 months ago: Phones with most LTE/5G bands

tl;dr: iPhones and Pixels cover the most bands. If you're buying in North America and only concerned with Europe, you can probably get away with some Motorola and nicer Samsung phones as well.

The cheapest good option would be a secondhand iPhone--even the iPhone XR is still supported by iOS 18 and you can score one of those for $150. The 12 series adds 5G support along with some other features so that'd be a better option but will set you back $250-300. If you're looking at new phones, the Pixel 8a is (IMO) the only logical choice.

You only need an iPhone 13 for DSDS if you're trying to use two eSIMs; if one of your SIMs is a physical SIM you can do DSDS all the way back to the XR/XS. It's similar with Pixels, eSIM and DSDS support came along with the 3a but it wasn't until the 7 that you could use two eSIMs at once.