The best thing is to go to a well known comparison website, that has information on both the TV's and look at the specifications on both of them. Then if you Google both models of the TV's just to see if there are any sites that have reviews on them. Then at least you can see if there are any bad reviews. If you do put the models of the TV's on the comparison site, they may find the TV's cheaper else where, but do look at the reviews especially from the customers from the store. Also I know this obvious, but check out if you get delivery service in that, because sometimes when you go to high street stores they will add delivery as well as some of the web sites, but there could be some that don't.
When I bought my TV 3 months ago, I looked at the amount of money I had to spend, then looked around for the best possible model for the price, and you will be surprised at what your money can get you, if you look around, but always remember the reviews from customers and the specifications, because I know this is obvious, but just because a TV looks nice,doesn't mean that it will have all the latest features etc. If you are like me you will want to make sure its as future proof as possible, like has it got High Definition, what are the specifications of the tv's picture, does it have any awards from other sources, that is where Google comes in handy. LOL. Because there will be a site that will cut out all the jargon and will talk English.
I hope this helps.