It's cheaper to buy a kit as long as the kit has pretty much what you want on it and you don't swap out a bunch of stuff right away.
Another thing to consider is how soon do you want it? Del-Ton is at least 4-6 months behind (think Christmas) on kits and on certain hard to get individual components like BCG's they are 1 year out.
J & T is better (time wise) and they have lots of options on their kits so you should be able to get pretty much what you want but figure on at least 6 weeks depending on what you order, I ordered a DS-4 kit from them and it took 6 weeks to get and I have a middy kit ordered from Del-Ton that will get here when it gets here
I have hard that M & A gets kits out quick but you have to call them and get what ever they have in stock at the time.
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