The RV market has seen such an ebb and flow in the last 2 years it's nearly impossible to know if you are getting a good deal. Prices were stable and the scenario you describe of 25-30% off MSRP was the norm. BTW MSRP is supposed to be set at the factory and dealers are supposed to abide by a MAP (minimize advertised pricing) to keep the dealers from the same manufacturer from putting one another out of business. But all that changed with Covid. Crippled supply chains, manufacturers losing employees, supply was at an all time low. Meanwhile, covid made conventional travel come to a halt. So everyone started buying RV's. Dealer lots were empty. Supply low and demand high to the extreme. Prices no longer needed to be discounted and people were falling over themselves to over pay just to get an RV. Now the market is saturated, supply chains restored and demand is low. Anyone who wanted an RV bought one, seasonality, conventional travel is restored and interest rates are at a historical high. Supply high, demand low. Ok, that was a lot to unpack, but if I were to forecast, come spring you'll see the used market saturated. But unless the Fed loosens the grip on money, people will still be hesitant to buy. If you have cash, it might be your time. But getting a good price and financing costing more, means your good deal still costs you more in the long run.
All that said, the only real way to know if you are getting a good deal is a LOT of homework to see what like models are listed and have sold for and a lot of shopping around and asking for best and final price. In the end, the seller and the buyer should both give a little and you just need to feel good enough that you got a deal that works. It's still a depreciating asset so it's always going to be worth less than what you paid.