We stayed in Surrey last year and I figured I should post my experiences in case people are curious how feasible doing that is.
I ended up choosing Surrey because I'm a Marriott rewards member and the civic autograph collection hotel there is significantly cheaper than similar Marriotts in Vancouver. Surrey isn't the nicest city so I definitely cannot speak to other lodging. However, the Marriott is about 100ft from the skytrain rail. Which was super convenient and nice. At around $100 USD per night you get a ridiculously fancy room.
The skytrain is super nice, you buy a little plastic card for a dollar or two and then you load it with rides. The day pass seemed to be the best value from Surrey as it was unlimited for 10 dollars (CAD I think).
If you have a big pc/monitor I wouldn't recommend staying in Surrey as it's a 45 minute ride to waterfront by skytrain, unless you have access to a car. We drove up from the US last year so we drove our PCs into Vancouver and parked in the garage for LTX19 and used the skytrain for everything else (we visited for a week).
Surrey isn't the safest place, there is a lot of homeless/strung out people. They generally seemed to keep to themselves but I'm also 6'3' Army vet with a large beard so experiences may vary. I will say I always had my guard up when I walked around Surrey. On the morning walk to the train station you get to dodge puddles of vomit from the night prior so that's fun! There is an amazing Pho place located next to the skytrain station that I will definitely be going back to next year! It's called: Phở Tâm Vietnamese Restaurant.