The unit that pretty much all tuners use is the Alientech ST3 which is an ok tool, it doesnt reset flash counters but thats not a problem for 99% of people.
Pay the £249 and get it logged by someone that knows what they are doing, maybe a dyno test is a good idea as well, you wont have the adjustability and precision of a well set up map such as Revo but you get what you pay for, as far as generic 'flash' maps go you cant complain at £249.