Yeah. Just pay in what you can every time you reach a new zone, and once you hit the 100.000 mark for that zone the shortcut will be built.
As for the kissing booth, like with the stores the price increases per level. 20.000 for a life I don't think is unreasonable at the start, as long as you don't have the Kapala. Equipment, especially at the start, is almost always worth the price. You'll probably need it to get very far, and things like the climbing gloves will allow you to reach places (and treasures) you couldn't otherwise.
I don't find things like the bow, pitching mitts or those spectacles (especially if you get the Udjat Eye) to be very handy, but things like spring boots, climbing gloves, a cape (or better: jetpack), sticky bombs, a gun (or better: shotgun), etc. are really useful. And you can never have too many bombs and ropes.
The teleporter is handy too, but I always end up killing myself with it