Advice
Most people plan on just getting married the once, so obviously it is going to be a very special day, so don't cut corners when booking the nights entertainment, we find a lot of people tend to ring around for the cheapest price and not paying attention to what is on offer, my question to you is "If I went out and bought a £200 pair of scissors, some peroxide along with some hair colour, would you let me do your hair for your wedding?" I will do it for £20
Your most probable answer is going to be "No Way" the reason, you would want to find out if I'm any good and certainly would not risk it all going wrong for your wedding.
So why take the same chance with your DJ, because making the wrong choice will not only be disastrous for you, but all your guests too, the simple answer to this is ask questions, whoever you call should be in a position to discuss how your evening will be, at the end of the conversation you will know if that person is the right one for your event.
Hotel Scams
Some people choose to have their reception in a nice plush hotel, they also find that their DJ is going to cost in the region of £300 plus vat, now this is fine if you are a vat registered company and can claim it back, but why should you have to pay vat for a service where more than probable the DJ is not vat registered? furthermore the DJ at the hotel will only be earning around £190 so the hotel had added £110 for themselves plus to ad insult to injury ad the vat as well, now if you say you want to bring in your own DJ they will probably request a copy of public liability insurance along with P.A.T certificate, we carry all of these.
You may also find that a hotel will say, you can bring your own DJ but we have to charge you X because we have to pay the DJ this is all nonsense, I do not know of any DJ who has a written contract with any hotel stating this, so should you ever get billed any amount demand a invoice and receipt from the said DJ.