The shop has to pay for it. Do not buy it if it has a RI because its going to cost you another $80-100 for the vet visit.

Tho if its just a mild RI you can bump the temps up, and the humidity to get the immune system working better.

I BP i picked up at a show for $20 has a RI. She was just like hissing and had a bit of bubbles iv kept her humidity around 80-90% and her ambient temps around 85 with 92 hot spot. Havent heard her hiss or any bubbles since mid last week. But if you try that be prepared to goto vet if it does get worse