How Does One Get An 1803 Silver Draped Bust Dollar?

If you are just looking for a silver dollar with that design, the least expensive year is 1799. I am not sure which price guide you are quoting but they seem quite low. Bust dollars in problem free F and EF are like $1400-1600 and $4000-4500 respectively. If you just looking for a coin with that design, the half dollar is the least expensive option. A problem free VG/F can be had for around the same price as your dime.

If I were in your shoes, I would aspire for the half dollar and put the dollar dream on hold for awhile. Still get the design, still get a good size coin, and much more affordable.

I'm to late with that one. That is what I was going to say.

Here is a problem we and many other face. If your young, you usually can't afford expensive things. As you get older, now you can afford them but now the prices have gone up so still can't afford them.
At your age so much depends on relatives, friends and possibly even a nice neighbor. If I were you and could find the coin you want at a coin store, coin show, on line, etc. then the thing would be to try the please, please, please lend me some money.