I'm not sure what brand I have - I bought it used. I'll have to look to see if it has any markings on it. It's a factory made acrylic wet/dry. the complete system "ready to use" with filter, overflow box and and almost new MAG return pump was only $ 50.00.
I had been looking for a used setup at a reasonable price for a couple years. In my area at least I found that first - wet/drys or sumps rarely show up for sale used and when they do they are rather expensive for used equipment IMO. With wet/drys falling out-of-favor so much in recent years you would think people would be giving them away. My guess is most people simply converted theirs to sump only setups.
As for cheap - the most cost effective way would seem to be to use a smaller glass aquarium as your sump. On-line you could probably get a new overflow box/hose setup for less than $ 50.00. The only item remaining would be a pump. I'm guessing you could get something large enough new in that $ 50.00 range too.
Others on the forum are probably in a better position to suggest size since I'm new to the sump game myself. If you would put the sump in your cabinet that would dictate the size. If next to your tank probably the bigger the better from a water quality standpoint. On the other hand the higher the volume of water means more salt, bigger water changes, possible larger heater, skimmer etc. so you need to balance that too.