If you mean Switch 1, I recommend Facebook marketplace or similar sites honestly.
I always see bulk switch games for sale for a flat price usually, and I get good deals.

>>747617526
but they don’t usually have the weebshit i want like a physical copy of engage that isn’t $80

>>747619026
Well, that's true, but still worth a try, ya never know.
You also could try importing or sites like Playasia. A lot of jp releases have english included anyway (look up to be sure), and can be cheaper usually. It really just depends what you want and if you care about what rating symbol is in the corner lel.
If not, just be very patient and bid on used copies on Ebay. I also have luck at pawn and hawk shops too.
Either way it comes down to luck.