I too dislike the "Throw away mentality" that is so prevalent in today's society. Products these days are made to have a short lifespan. Manufacturers want you to replace than to fix. Mechanics no longer fix cars anymore. they just replace the entire part. That's why they are called technicians instead. Anyhoo, I do agree with cyclocommute on this one. A broken frame like the top tube is a major structural damage. Given that OP has ridden the bike for more than 2 decades, I think it is nothing wrong to buy a replacement rather than to spot weld the old bike for nostalgia purposes. It can be dangerous too.