Hi there, I don't know much about bikes and would like to ask for your advice.

I'm looking at two used bikes: a GT Airstream and a GT Streamline, both from about 1999 or 2000. Both would need a bit of work, like a new chain and cables. Basically my question is, what should someone spend for both the bike and the labor to get it into good shape? And at what point would these particular bikes not be worth it?

I don't know enough about bikes to know if the quality of the components are such that it would justify fixing up or if I would be better off getting a newer used bike. So can you tell me how good the components standard on these bikes are compared to today's components on an entry-level hybrid? Thank you!

Specs for Airstream from Bicycle Blue book:
Wheels and Tires
Hubs: Shimano Altus
Rims: Araya PX-645, 36-hole
Tires: 700 x 40c multi-terrain
Spoke Brand: Stainless steel, 2.0mm straight gauge
Components
Brakeset: Shimano Altus brakes, alloy levers
Shift Levers: Grip Shift MRX
Crankset: Shimano Altus, 24/34/42 teeth
Pedals: Resin
Bottom Bracket: Shimano BB-CT91
Rear Cogs: 7-speed, 11 - 28 teeth
Seatpost: Kalloy aluminum suspension, adjustable
Saddle: GT
Handlebar: High-rise steel
Headset: 1inch sealed mechanism

Specs for Streamline from Bicycle Blue Book:
Wheels and Tires
Hubs: Aluminum, Q/R
Rims: Alloy, 36-hole
Tires: 700 x 42c GT Streamline Sport
Spoke Brand: Stainless steel, 2.0mm straight gauge
Spoke Nipples: Brass nipples
Components
Brakeset: ProMax linear-pull brakes, GT Streamline levers
Shift Levers: SRAM MRX
Crankset: Shimano C-201, 24/34/42 teeth
Pedals: GT Streamline Sure Grip
Bottom Bracket: Shimano cartridge
Rear Cogs: 7-speed, 13 - 28 teeth
Seatpost: Kalloy aluminum suspension, adjustable
Saddle: GT Streamline
Handlebar: GT Streamline
Handlebar Stem: Aluminum, high rise
Headset: 1inch sealed mechanism