Another valid option is to buy nothing!
Don't get me wrong- there's cheap hoses and nice hoses and cheap donuts and fancy screw in elbo's.
On our maiden voyage, we were "forced" to buy a foam donut for the massive price of 2 bucks....I did have a cheapo 20 ft hose that I used instead of the 10-ft freebie...
That kept us going for 10 years...5 years in I got the clear elbo and just last year got the Rhino...it's all nice, but you do have holding tanks that will take care of you for a day or two (or a week or two) until you can run out and get whatever extra do-hickie you think you just can't live without :-)