This is going to be tough, a quality lab balance is needed for more than "kitchen chemistry" Some specialty or health food stores may have a small accurate scale for weighing out tiny amounts.
Good quality lab balances are often useful outside of labs. When we broke up a lab I used to work in, the engineer took one home. He said it would be very useful for mixing epoxy. Instead of eyeballing amounts, he could now be accurate with the masses of the two-part mix. So maybe a hobbyist along those lines would like to split the price of one with you.
In my old days, I'd read descriptions of making your own two-pan balance, with any old fulcrum. But for real good accuracy, you'd want a sapphire knife edge, and that is part of the source of the high price. Plus, with a two pan balance, you now have to acquire calibrated weights to do a massing.