Help me understand the concept of 'Prize zones' to buy extension tickets in Frankfurt

I think you are asking about the Zuschlag ticket?
For example, I have a monthly ticket that covers Frankfurt and the airport. If I want to go to Mainz, I buy a Zuschlag ticket.
When purchasing, click on the Zuschlag button and then the ticket machine will ask you what zone.
My monthly ticket is a P-3. Yous may be different. Take a look at it and come back and tell me. Look on the RMV website and it will list the Zuschlag prices for each zone, starting at P-1, P-2, P-3, etc.

I am talking about extension tickets, not sure if is the same as 'Zuschlag'. Yesterday i bought a monthly pass and the preisstufe on it was 4. I guess whenever i buy an extension ticket to anywhere, i need to select preisstufe as 4. Is that right or i am missing something ?
I still do not understand the concept behind it. Preisstufe translates to price-level but looks like it is more of a 'zone' thing. I need to understand it properly to avoid buying a wrong ticket in future as i will be going to a lot of places around wiesbaden in summer.

Today i asked the same question to the representative at DB information outlet in wiesbaden main station. The person told me that wiesbaden is zone 13 and i should always select 13 while buying any extension ticket. Now this has added to my confusion. I rechecked with the person by explaining in more detail but the answer was the same :-\

Yes, they are called extension tickets. So instead of me having to pay the full price for a ticket to Wiesbaden, I just pay the extention /zuschlag. On the RMV page they call them anschlussfahrkarte cause they don't have that part translated into English. On the ticket machines, they do.

If your monthly/weekly ticket is a Preisstufe 4, then you will pay less then I do with a Preisstufe 3.

Checking the Frankfurt to Wiesbaden tickets, normal price would be 8.85 € one way. I would pay 5.35€ for my anschlussfarhrkarte because of my PS 03 and you would pay 4.45€ for yours.

You can't use it for day tickets or group tickets though. Only on one way tickets.

Just type in the name of the city you are going to. Forget about that zone 13 thing. The price comes up automatically. The DB folks don't really know about the RMV information.

I have been doing this for years with my monthly ticket and I travel all over this region doing just what I told you. My tickets are always correct when checked by the controller.

If you are on FB, the RMV has a good page and they will often answer your questions quickly, and in English.

Prize zones?

Pretty sure the OP meant Preis, but didn't know how to spell it.

I meant to say price-level. This is what i get when i translate preisstufe. I was confused because the English version on ticket vending machines talks in terms of zones.

I did an 'extended' journeys and now i have a couple of more questions:

1) I have a monthly pass for Wiesbaden and Raunheim area. This pass allows me to travel up to Frankfurt airport. So i would expect that for journeys to (for eg) Frankfurt main stations, i will have to buy an extension ticket from Frankfurt airport to main station (2.50 Euro). But when i tried that at Wiesbaden station, i see no option to specify source as airport. I ended up buying the extension ticket from Wiesbaden to Frankfurt which was for 4.50 Euros. Coming back was ok as i had to put in the destination as airport. Is there no way to utilize additional zones in your monthly pass ?

2) Is this extension ticket applicable for all the connections you take (bus, tram, u-bahn) to reach your final destination ? I tried specifying a u-bahn station as destination but i think no u-bahn station was listed. I then specified a s-bahn station and used that ticket to travel on u-bahn as well. Is this extension ticket valid for complete zone ? How long is it valid after the time of purchase ?

Your problem is a bothersome one and one that happens to me too. My monthly pass is good for the airport, but I can't get that extension ticket to go to Wiesbaden while I am in Frankfurt. If I wanted it badly enough, I would have to get off the train at the airport and buy it there, then jump on the next train. Bit of a pain, but that is how it works. If you don't mind waiting 15 min. on a train.

Yes, your ticket is valid on all forms of public transportation. Trams, buses, U-bahns and S-bahns.
It is valid for about 1 - 1.5 hours after purchase. As long as you are traveling in the same direction going from point A to point B. It is not valid as a round trip ticket even if you are making a quick trip into town. For example, the train from Frankfurt to Eltville takes almost an hour, then one has to wait 10 min. on the bus up to Eberbach. The ticket is still valid cause I am still moving in the same direction basically.