First- If you don't mind some advice: Don't rule out arco playing completely. Even if you don't plan to join an orchestra, arco practice is the best way to develope your intonation- and it's a lot of fun when you get half way decent at it!

And despite what some people may tell you: You CAN bow on guts or Spiros, it's just not as easy as it is on some other strings!
Gut maintenance- yes, there is some work involved, but it's not laborious. Depending on the climate where you live you may need to do more or less- lots of changes from high humidity to the lack thereof and back can cause the biggest problems. Generally speaking though, you may need to oil them from time to time; and they sometimes will get little "whiskers" that you have to clip off.
Gut strings that have a winding on top of a gut core can be tough to keep in tune- the two materials react differently to environmental changes. It has been my experience that plain gut strings are very stable, and I live in a climate that is hard on gut strings.
Spirocore cost- shop around a little, you might find some deals. I usually buy my new steel strings from Gollihur's Music- and they sell them for about two hundred bucks, and they used to include shipping in that price.
Buying a set used is a great way to go too! Some people love the zingy sound of a new, fresh set- so they like to change them often and sell the "broken in" strings here on Talkbass. It's a GREAT symbiotic relationship- like the little birds that go into crocodiles mouths to clean their teeth!

"Everybody wins!"
Good luck!
Joe