Hello prodder
I believe the average charge is around 660 dirhams for a single,i dont know about the microlights or the seneca.
If you work on an exchange rate of (approx) 5.45 dhs per uk pound it will give you an idea of the cost,sorry but i dont know what you collonials use for your rate but you can work back from there.
I will get you a phone number for the Fujeira aviation center and post it over the next few days,the dubai flying club has its own website which you should be able to find and i will try and get the RAK number for you.
Good luck