£3,000 isn't that expensive in the grand scheme of things, mine was double that! That said in taking Decleor on I covered that cost quickly within my first year & have made a very big profit.
However, if you are risk averse or cannot secure these kind of funds from a loan or similar, then there are plenty of other ranges that don't involve this sort of outlay, although every range will have an amount you'll need to spend before the range becomes useful.
Take the "minimum opening order" issue that is much vaunted. You may be able to open an account by just buying a cleanser, but it's not going to be very useful for providing a range of treatments! So don't be allured by the "no minimum opening order" statements, rather ask how much you'll need to spend to get a range of products that will enable you to carry out the treatments.