Personally, I think that's too expensive just for practising or figuring things out.I think I've found the tent which I am planning on buying, whether temporary for practice or to take on the big trip - The Coleman Phad X2. RRP £180 - 200, I've found it at £109. Thought I'd mention it here to see what you think of it (You're probably pretty sick of me now LOL). Its more money than what I'd pay for a temporary one and the RRP is around the price that I would pay for the big trip but, as you say I've got 2 years to find that one and I may find a better one by then. At £109 I think it is a bargain.
I know someone who'd say "It's very easy to go broke saving money!".
It's also heavy for what you're getting 3,4 kg.
Good advice to look at backpacker's sites.
Look for someone local, second hand tent. Get them to pitch it out for you, go through all the things to watch out for.
Seriously, I wouldn't consider anything over 35-40 quid.