It really depends on what you consider to be a reasonable cost.

As others have stated, you'll most likely need new tires, tube and rim tape (if the existing rim tape is rubber) plus new brake pads. The saddle isn't really an issue because you might have wanted to replace it anyway if it was in good condition but didn't suit you. Your handlebar tape might be okay too. I use Renfrew brand hockey tape for my vintage bikes because that tape is very durable and looks a lot like the old Tesla cloth bar tape.

Cables for the brakes might be needed if the ones on the bike are badly deteriorated. Otherwise I'd just squirt in some good oil into the cable housing and work the brakes a bit. If you do that with the brake pads off you'll get a lot more cable exposed when you pull the cable and that'll help the oil penetrate further into the housing length.

Price out what it'll cost you for tires, tubes et cetera and then see if that price fits within your idea of reasonable. Also, this will only be relatively inexpensive if you can do all the work yourself. Your bottom bracket and wheels will need to be cleaned out and new grease put in as the old grease is probably hardened.

If you're doing this in order to sell the bike, then no, it's most likely not a reasonable price as you'd be hard pressed to recover the money let alone your time.

Cheers