Hi David,
Are you looking for an estate agent or property management company?
If you buy from a developer you often avoid the estate agent/makler fee which in Bavaria is around 3.5%.
Some estate agents will also have deals with the vendor that their fee is included in the sale price.
The advantage of this model is you need less of your own capital.
An estate agent and the developer will both vet prospective tenants and let the flat for you. Normally they charge the new tenant about 2 months rent, so its good money for little effort and in my opinion they're not really doing you a favour - although they sell it as such.
However as an owner, what interests me more is the handback process. In Germany you have to hand back the flat in the condition you got it, wear and tear is not really well defined. I choose a estate agent/property management that are also responsible for hand back, as I feel it protects the investment.
Do you expect your agent to help arrange financing, many of them will have contacts to brokers/banks. You might want to consider an agent with an in-house finance team. I'm pretty sure they earn form this process as well.
Tax return- I live in Germany and have a tax advisor which speaks english, you might want to consider a company again with an in-house team.
You may want your agent/property management company to raise the rents for you. In my experince this paid off as a tenant is a member of the mieter verein and the property management company used their inhouse lawyer.
Another feature of some agents is they bundle the notar and tax into the price, which means you can finance more.
So to cut a long story short my agent is a full service company, not sure they're cheap but I'm happy, will send you details if they're what you're looking for. But if I were choosing a new agent I would put together a check list based on the above.
regards,
Martin