That depends less on your level than on your stile of playing. How much time do you invest? How many times a day can you play? How many close friends do you have to support/are supporting you? Are you ready to invest real money?
If you can farm a lot, you can grow crops and sell them, so that you will have plenty enough coins not to need any jewellery to sell. And you will have enough shovels etc. to mine.
If you farm several times a day and support others, you will most probably run out of jams and need Tom to get them for you.
If you farm less frequently, you might have more jams and cheese than you need and could support your friends, when they need them, and have them help you with cream and sugar, which will be more of a problem for you.
To get the best use of Tom, you need to send him puncutally every 2 hours. If you can't farm during daytime, this might be a problem.
If you're willing to pay real money, you can just hire him whenever you want and for whatever you want. It's not much real money, actually. On the other hand, if you want to feel proud of your achievements, you might not want to spoil things that way.
Personally, I wouldn't want the stress and bother of sending him every 2 hours during several days just to get some diamonds to send him again. I get enough diamonds from boxes and such to send him occasionally for jam.
Greebie
Willowbrook Farm
Level 71
