Bernina's seem to like Isacord threads. I'd sign up at a local Bernina dealer for their newletter & watch for sales. If the dealer has many in store events they usually offer a discount storewide. You could also do a search on line for a better price, but you also need to factor in shipping costs. As for the many colors designs require.....I have about 170 colors. I chose 3 or 4 shades from each color & when doing a design I pick one that comes close to what the design calls for. You don't have to buy every color. When using metallics slow the machine way down, use a thread net & a metallic needle.