Sears free spirit 3 speed 26" man's bicycle without seat and post - what's it worth?

Someone is selling this bike and asking $20. The tires have serious dry rot but still hold air. The chain is rusty but flexable, and there is some rusting on wheels, handlebars etc.. Don't know age, I think 70's. It's dark brown with orange and yellow stripe detail, "free spirit" is written across top bar, and "26" is written on seat tube. Sears emblem with 05-78 at bottom of seat tube, and 02 47268T13654527 engraved into headtube. Is it worth investing in new seat and post, plus possibly new tires in near future, or should I pass on this? The post is very thin - 2.5cm. What will seat and post cost ? If owner finds seat is it worth taking given tires and rust? He claims the bike is worth $100 - $200 as is. I'm 67 and just plan to ride locally around town, no more than a few miles at a time. (I'd really like to hear from "mirageguitarworks" - others also welcome to respond). Thanks!

Thank you all very much for your answers - I'll take your advice. So now what should I look for at yard sales - what's good and what should I stay away from?

I actually like the old Sears bikes. The bike you are looking at was made by Huffy in- you guessed it- May 1978. Stamped sheet metal brakes, full chainguard, Shimano 333 rear hub.

Unfortunately the bike, based on your description, is parts fodder. I love old bikes but this one would find it's way in the trash. In perfect shape I have seen them at yard sales for $10-20. My guess if you look around you'll find dozens of them at this price. Keep your money and drive around some weekend looking at yard sales.

EDIT: On a personal note, a very close friend of mine who just turned 80 (!) still rides 3 miles back and forth to work (!) almost every day. Up until a couple of months ago he was riding a 1972 Schwinn Collegiate 5 speed. For some reason I felt bad about what he was riding and bought him a Raleigh Detour for $400. Worth every penny. I was also the mechanic for a group of seniors that participated in the RAAM- Race Across America. The youngest of the team (besides me) was 67 and they all made it in one piece. One of the guys, 77 years old, said that he feels better now than he did at 50, but started to ride because he was tired of waiting to die. A bit sad with a happy ending, eh?

EDIT 2: Look around for bikes that look clean... no rust and few signs of wear. This is pretty easy to spot by looking at the handgrips, the cable housings, and the pedals. Search for bikes with Sturmey Archer gears (if you want a 3 speed) and take a ride on the bike if possible. For Sears, Huffy, or Murray bikes expect a price range of $20 to $40. For Raleigh, Hercules, or other British made bikes (look on the headbadge) expect to pay up to $80. For Schwinn, well, I would tend to avoid them because of the problem in obtaining replacement tires (they had their own special size). If you find a bike you like and are able, post it in this forum and we'll try to help you out more.

This bike is not even worth $10.00. If the tires are that dry, rusty chain. Those will have to be replaced. Mom had one of these, except I think it was a 5-speed. It was blue, it didn't hold up very long. My grandmother worked at Sears in the cataloug dept. (where you call your orders in). She always said don't buy anything from Sears, because most things don't hold up. The bike started to come loose, the appliances didn't last as long as they should have. Yes, it was a free spirit. I'll never buy any appliance or anthing like that from Sears. You can do what you want to.

This bike has little to no value. Brand new it cost about $100 30 years ago. The original saddle and post were very cheap as well. Expect to replace tires and tubes, that'll be $30, plus a saddle and post probably about $20 or so and maybe a chain $15. You still can't be sure the rest of the bike won't need maintenance, like wheel and crank bearings or the 3 speed hub. The price goes up if you have a shop do it.

You can always find a good old bike in much, much better condition for the $70 to $85 it will take to fix the known problems on this trash day special.

I ain't no "mirageguitarworks" but this is a no-brainer.