Personally I would peel it off. This would help you reselling it later, this is not about hiding the actual price as anyone that want to buy a lego set may or may not have done their research on the set. It doesn't help if you still need to explain to the buyer why your set is more expensive than the price on the price sticker. A Tip - for those hard to peel sticker, I would use a hair dryer, mid warm setting to loosen it before carefully peeling it off.

This is the bane of all Lego investors, especially when picking up off store shelves, I always try to remove and sometimes it's basically impossible not to damage the box. It's just one of those things, which you can't really complain about, because when you normally pickup from a store you tend to be buying at a large discount.

I recently purchased a few investment-worthy Lego sets from a local retailer. The boxes were in excellent condition, however, in the top-right corner of the front-surface of the box was a large sticker featuring the text "ONLY 49.99".

Coincidentally, I thought I would begin some discussion on the topic of price-stickers from an investor's point of view. I begin by asking, what do you do when you purchase a set that has a price-sticker on it? Do you peel away the sticker, cover it up in some way or leave the sticker as it is on the box?

I use a heatgun and peel them off. Never had an issue. I never leave the sticker on as some buyers will use this as an excuse to extort a partial refund on a certain selling platform.

This is the bane of all Lego investors, especially when picking up off store shelves, I always try to remove and sometimes it's basically impossible not to damage the box. It's just one of those things, which you can't really complain about, because when you normally pickup from a store you tend to be buying at a large discount.

Just use a hair dryer an heat the sticker. Then just slowly peal it off while still aiming the hot air at the under side, Ive done this hundreds of time with success every time.

So I never remove my stickers but I only sell on Amazon. I even asked an Amazon rep about stickers/box condition last year and they said that stickers don't matter and box condition is a judgement call.

Maybe I'm just lazy...I'm thinking about starting to remove them though now that I'm planning on selling way more volume.

Yes, always remove them using a heat gun or hair dryer. You're asking for an issue if you leave it on. Unless of course you're selling it cheaper than the sticker states. 

Another me to on the heat gun.  Start slow, don't cook and discolor the box underneath.  I have had some vintage board games with packing tape and duct tape on them and it did a great job.  Just don't be hasty.

Lighter fluid

Has anyone tried to get a sticker off an instruction booklet? They don't have the same glossiness of the box so I'm not sure if the hair dryer trick would work.