If I was looking at a house to purchase, I would consider sheet vinyl to be the lowest quality of flooring possible. It's a low investment and if you are replacing old sheet vinyl, you aren't going to "lose" money. But it's not going to help resale value. More on reddit.com

Not sure re council. However, I do know sheet vinyl itself is classed as a waterproof membrane product. Would recommend thin lauan ply underlayment for better adhesion and just to smooth out the floor in general without having to go nuts. Make sure staples/brads are recessed. After installing underlayment, skim coat with ardex feather finish (it's a fine grade flooring skimcoat product) to tidy up joins and fill in any holes/gaps. Will be easier for you to just lay vinyl under the toilet prior to its install. "Sticky tape" (VHB tape is what installers use) is more for looselay products. Wouldn't recommend looselay products like that for a bathroom myself (they expand and contract a lot in new zealand conditions, even if it's only a small bathroom). Vinyl adhesive with a vinyl trowel, and use a dampened cloth to rub any air out from the adhesive starting from center and working out in a circle. You can do the sticky tape method, but do know that it's essentially loose and can easily tear. Not such a problem with looselay products as they're thicker and can tolerate more brutality when not 100% adhered. The reason they're charging 1.5k is they're including doing everything correctly the trade way plus labour, not because they're doing it the same way some random on youtube will. In this situation I'd probably recommend the floating flooring vinyl products (e.g Karndean's Korlok) honestly assuming no skirtings on yet. As long as the floor is flat enough, you can essentially skip the prep that would come with sheet vinyl; as long as you've got the floor cleaned up. More on reddit.com

No such thing as waterproof, even nuclear subs leak. More on reddit.com

The peel and stick laminate tile is amazing. I’ve had it in a bathroom for six years and it’s held up way better than I expected. Perfect for diy and on a budget. I used the farmhouse wood look one from Lowe’s. One or two boxes will do it for a small bathroom, and you can lay it fast! Just need a good straight edge and a razor knife, caulk and maybe fresh trim/baseboards. We will tile when our kids are grown and no longer dumping water and dirty clothes everywhere. But for now, this product has been perfect. More on reddit.com