Rooter
Money List Winner
As for me, I prefer booking tickets and hotels on my own. Agencies usually cooperate with hotels and thus you pay more than you could've paid if you traveled on your own. You can find cheap flights on skyscanner and then find a decent hotel for a decent price. For example, last year I got cheap tickets (it was sheer luck like it usually happens with skyscanner) and found this agency offering Calpe rental apartments and got a hotel room in 100 meters from the beach. I paid €400, and it's €100 cheaper than I'd pay if I used the agency's services.
To be fair to the bot/noob trying to sell holiday lets in Calpe. Its a beautiful town and if you go, climb the Penon de Ifach! Its amazing!!