you can't really depend on others to give you these types of answers, better to research the current trends, market, sales, etc. yourself so you know what to do..
i personally would'nt spend more then 100bucks on that if that helps at all..
Before buying a domain, you should try to think whom you are going to sell it to and what the benefit will be for the buying party.
I can't see how a business could take advantage of being named tubeload.co (nor even tubeload.com or youtubeload.com BTW). For me, it means nothing. May be I am missing something. So, I wouldn't even pay regfee for this domain.