Hi.
If you really want to have an enjoyable time woodworking, then why not invest in something that will do the job properly. You will not cut fine dovetails with predictabiliy and enjoyment with a 12 inch tenon saw, even if you are a seasoned pro. A raw beginner will fail and become disheartened. Get the right saws for the job and you will not be hamstrung from the off and then you can really learn how to do things properly. The most significant reason why most woodworking novices give up, thinking they can't do things the way they see others do, is because they do not buy suitable tools which will never do good work for them. Good tools are an investment, but once purchased will last a lifetime, which is better economically than buying dross and tossing them, to inevitably buy the right one later, or worse just never bothering again. You have to realise that much of the advice given in these forums is from people who do not want to spend any money and convince themselves that buying cheap is all that is needed and things which cost a little more are not necessary. Beware of this advice as taking it will inevitably mean you will not get your tools sharp or your joinery crisp. I would recommend a 10 inch Western dovetail rip saw which will do fine dovetails and small tenons. The shoulders can be cut with the same to a knife line, though eventually you will want to get a matching crosscut to make these shoulders finer. Add the equivalent tenon saws when you want to do larger tenons and halving joints. Obviously, if you are going to start with tenons and move to dovetails later, then reverse the order. Once you have got one or two fine tools, then maybe you will want to get some good used saws, as you will then know what you are looking for and what charactreristics you need when re-sharpening, which isn't too difficult to learn and a necessary skill to aquire as your saws will need re-sharpening from time to time. You will never regret buying good tools but you definitely will poor ones.
Mike.