We've been to Tampa/St Pete for a couple of conferences and we stay at the Don Cesar. It is an old hotel, the pink one and we love it. You might check them out and just find out what the rates are. I love that hotel.
We have several conferences a year alternating between FL and CA and typically get a conference rate of about $200 a night. Hubby also travels a lot of work and I am lucky if I can manage to get a SAFE place for him anywhere under $200 a night, even with our Corporate discount with Hilton.
That said, if you book on Hotwire, Priceline, and discounters like that, you do not know where you will be staying until you finish and pay for the reservation. In the long run, it is better to go directly through the hotel chain website to located special deals, etc. MANY hotels have valet parking only at $30 a day, required $30 a day for the spa feature and not every guests takes advantage of the spa. You can negotiate your own rate if you speak with someone specifically at the hotel where you are interested in staying.
Also keep in mind... if you do book on Hotwire, Priceline, a discounter.... your room can be changed at any time without you knowing it until you go check in. Why? because if a frequent guest (rewards member - me, sales reps, etc) show up to get a room, you are automatically bumped to another hotel.
A lot of the more economical chains are not located on the beach. You can save a little by booking a block or two from the beach.
Have fun! We enjoy Tampa when we are there.