Have no experience with the ASTROS I am sure they are good but they are $100 more and my PX4s work great and have great battery life. Plus you can charge and use them at the same time. I would suggest reading reviews about any you consider.
picked up my astro A40s for $189 at gamestop 2 months ago.(2013 version).
I tried like 5 different sets and the Turtle Beach XP510's work amazing. SOund whore people so bad. Software lets you tweak the hell out of the settings.
I have a set of tritons 720s and they're not that bad for sound whoring. The only problem I have with mine is it is hard to talk to anyone during the match, because they are drowned out by the game. If you could wait and save up for a bit I would go with the Astros, a buddy has a pair and he swears by them..
Hope this helps..
What I did was take out the microphone part and just used it for hearing things in the game. Then I took the earbud microphone that came with my PS4 and used that it works a lot better.
Just add a few more bucks and get astros if thats the case. In my post below this one i reccomended similar performing headsets for way cheaper
If your budget is 100 pounds I would recommend the playstation gold wireless headset, a few weeks back I was looking for a good headset and thought about buying one of the turtle beach series but the really good ones are a bit expensive and like you I was on a budget.
I ended up buying the sony headset as they were recommended to me by a buddy of mine who works at gamestop and they have not disappointed me so far... Battery life is very decent (4-5 hrs of continuos gameplay) they have surround sound, very neat quality and they are quite comfortable to wear for extended gaming sessions. You can use the same cable you use on the dualshock 4 to charge the headset and even download an app on your ps4/ps3 to customize the audio settings.
Btw, I paid $120 at gamestop for them ($100 for the headset + $12 for 1 year protection plan + taxes)
Never ever ever waste your money on Turtle Beach they are built cheaply and break fast. Go with Tritton's or Astro's if you want sound whoring headsets, those are the best 2 on console. They cost a bit more, but you could probably find them on Ebay for a good deal, just make sure they have a return time so you don't get screwed by someone. I have had TB PX21's, XP510, X32's and none of those lasted more than 3 months. The PX 21's wire ripped out the headset after a month, the XP510 wouldn't hold a charge on 2 pairs from Gamestop, and the X 32's left ear speaker blew after 2 months of use. I have had Tritton AX720's now for about 2 years and they still work as good as the day I bought them. I bought Astro A50's the day they released and have nothing but great things to say as well. The sound on Astro blows every other headset out the water because of the mixamp they come with.