I think you'll have trouble getting a decent place in your budget. Try Courtyard by Marriott (Marriott Village), they have Spa King Rooms but I think they run more than $100. Caribe Royale also has rooms with whirlpool tubs but I think those rooms go for about $150. Hotel Royal in DD also has rooms with whirlpool tubs, unless it's peak season they honor 50% Entertainment book discounts. Many of the offsite condo type resorts also have rooms with whirpools.