Need better range

I have an old wrt54g Linksys wireless router, Would it be wiser and more economic to buy a new one or add better antennae to it for a bigger, better range?

 

You could buy a range extender . . . I have used a Netgear WN3000RP that worked very well (got a manufacturer refurbished one off eBay for around $40US. That might be cheaper then a whole new router . . . but I'm not too savvy on the range capabilities of newer wireless routers.