I researched the best bang for the buck about a year or more ago and came up with Creality 3d as the biggest and most range of options for accuracy, DIY-ness, options, etc for the money. Didn't actually purchase at the time but this thread has me strongly considering again. Here is a review of one of them and also a link to one with a bunch more options below to let you see the differences and many, many options to consider.
https://www.banggood.com/Creality-3D-Ender-3-V-slot-Prusa-I3-DIY-3D-Printer-Kit-220x220x250mm-Printing-Size-p-1278399.html?gmcCountry=US¤cy=USD&createTmp=1&utm_source=googleshopping&utm_medium=cpc_elc&utm_content=frank&utm_campaign=pla-mix-us-pc-0626&gclid=EAIaIQobChMIkvmG5ebj4AIVhMhkCh35awCoEAkYCSABEgL1a_D_BwE&cur_warehouse=CN
I don't know about buying from the site above but it has good pictures, descriptions, videos, on 3D printers so you can learn about them before you buy from wherever.