Although the entry to the Trinity Monastery of St Sergius Lavra grounds is free, there is a multilanguage sign at the entrance informing that for taking photos a photography pass for 100 Rubles (ca. 2,20 Euro) should be bought.
As I didn't see anybody buying this pass, I entered the grounds without buying it either. Inside the monastery grounds I saw quite a few people taking photos, so I did so as well and nobody really complained.
Only once I noticed a Japanese tour group with this photography pass, which is actually only a sticker.
So when you are on an individual trip, don't bother about buying this photography pass. It mainly seems to be a tourist trap.
There seem to be two hotels in the city. One that does not accept foreigners and one that accepts them but only at a 400% higher rate! When confronted with this I explained tot he woman that I could find a cheaper hotel in Moscow, her response..."You aren't in Moscow"
"I will be in two hours" I replied and was on my way back to the trains station!!!
Unique Suggestions: Make sure you bring cash, the hotel doesn't accept credit cards....
Fun Alternatives: Make it a day trip from Moscow...it is easy to reach and aside from the monastary, there isn't much else to see.