Sensible pricing options for a tiered translation service on retainer? Or - how do I add value more without exhausting myself?

I’m an English man living in Germany.

As a side line, I offer German to English translation, interpreting and language lessons.

These do not provide a steady income, so I’d like to offer a service on a retainer basis - so and so many € per month allow unto so many lines of text translated/hours of lessons or or interpreting.

The customer benefits from a steady relationship with one supplier for all their needs, and I benefit from a regular income (with the added bonus of charging a minimum price).

My time is not unlimited, so I have tried to tier my offers.

For inspiration, I’ve looked at some mobile phone networks - for example, 50 messages and 50 minutes to anyone for 5€ a month (addition messages/minuets charged extra)

I’ve come up with the following:

http://www.rdturner.co.uk/Englisch_on_Tap.html which contains 5 (!) levels of service.

Questions:

• How do I make my offer more attractive/rational?

• How do I prevent myself from promising too much?

• What should I offer my best paying clients?

Because I have other commitments, I'd ideally like lots of translation and the occasional piece of interpreting - 5 or 6 customers sending me the lowest level of 50€ a month for 2 sides of A4 would be ideal…

What suggestions do you have? Any suitable links will also be fine.

Kind regards,

Edd Turner

P.s. for those who don't read German I'm offering to:

1. Teach and or interpret for 2 hours OR translate up to 50 lines of text for 50€ a month
2. Teach and or interpret for 2 hours and translate up to 50 lines of text for 100€ a month
3. Teach and or interpret for 4 hours and translate up to 70 lines of text for 200€ a month
4. Teach and or interpret for 8 hours and translate up to 140 lines of text for 400€ a month
5. Teach and or interpret for 20 hours and translate up to 350 lines of text for 1000€ a month

Extra hours are €45 each, extra line of text, 1€. For an extra 20%, you can 'rollover' outstanding hours/lines to the next month.

From a customer's point of view I think that price table is too technical and not very clear and concentrates on the means instead of the solution.

I would expect a service that charges a high price to completely solve the problem that the customer is having, an approach like this:

Communicating in sub-standard English can cost your company thousands of dollars a month in lost deals and a reputation for shoddy and inaccurate work. Let us solve this problem for you:

• Unlimited Proof-Reading........1000€/month.
• Unlimited Proof-Reading and Translations.........2000€/month.
• 20-hour pack personalized English coaching via Skype..........500€.
• 20-hour pack personalized English coaching in Person..........1000€.

I would go more that route so you can to get part of the "quality assurance" budgets that companies have set aside anyway, and then just have this renewed month after month. If your price is high enough and you get overworked, you could sub-contract your work out.