If the amp came with the squire which I am assuming it is probably like 10 watts. If that is the case it would be worth $90 together at the most.(and that may be pushing it)
Was the Squire made in Japan? What model, Telecaster or Stratocaster? The Japanesse series of Squires were actually some of the best produced and are highly sought after. Get me the serial# off the back of the headstock on the guitar, and I'll check it out on the Fender forums. I have 8 guitars so don't get excited, but I can try and get you a price check on it. As for the amp, unless its a vintage tube amp, they kinda age like milk.
The serial# says it was made In China by Yako in 2000. It does not give me any more info. Depending on condition and model (tele/strat) I'd say around $50-$100. As for the amplifier, it was a solid state Marshall. i'm going to say $50-$75 depending on condition. Those prices are a general ballpark, and if everything is in working order. If the guitar has a bent neck or damaged frets, and so on, its pretty much valuless unless you find a place that wants it for parts. Same for the amp. If its in decent shape shoot for $125-$150.