Your opening is intriguing. It has a clear voice, the speaker is identified. I love first person narratives because they invite you to get to know your character. I wonder how you feel about ending the first paragraph with your question rather than including the pricey/worth it statement.
I wonder also if the speaker would use the word "Beckoned" and "especially sweet". In this paragraph, those phrases seemed a little out of place. Is your character/speaker formal or informal? The word "Beckoned" feels not quite right. Try some variation of "Calls to me" or "invites me". These phrases seem more informal and balanced with the voice you are creating.
You gave me two paragraphs to get to know your voice and then thrust me into the story. I think you may want to either remove the two-sentence paragraph where you were traveling or give me more about the trip. Your character sounds like he would meticulously pack his equipment. When you add "A few months later", I was expected a conflict line, something that got in the way of the trip. Since there is nothing stopping the trip, maybe remove the "A few months later" and add a line about packing, or acquiring a new lens (just a suggestion).
"We dispersed to our rooms in the hotel." This sentence may need some tweaking or be removed all together. This is one of those opportunities where you can immerse your reader, help them understand that the character is anxious, fatigued, excited, etc.
Also "we"? (from the same sentence as above and the next paragraph. So far you have only introduced me to one character. I would rephrase this to "I" if you are not going to give me another character to get to know, or "The tour group." Since your character does not engage with any other member of the tour while taking photos, you may want to refrain from using "We."
"After a week, I looked at my photos on the flight home." What about expanding this to help me understand how the speaker feels about the trip. Something like, "After an amazing week I was headed home. On the flight, I was able to really look at my photos." Also, what about the rest of the unusable photos. Will the speaker hold on to them or delete them, tuck them away for safe keeping?
You used the word 'got' multi times in a row. Try some variety. "The credit card was overcharged and the trip turned out to cost more than I expected. If I paid it all at once, I wouldn't have..."
I really like the contrast in characters between Alexandra and the speaker. While her character is a little forced and over exaggerated, it does help your speaker express his anxiety clearly.
When your character is describing the cheetah photo and how he took it, I would like to have heard more from him. I suggest spending more time building up the moment. Help me understand that this moment was an exceptional and a time that our character will never forget by elongating the dialogue.
" stuck up dick, " Is this a typo? She may be stuck up, but it seems out of place and out of character for the speaker to have thought she was a 'dick'.
Ending with the moral of the story is an interesting technique.
The biggest piece of advice I can give you is to watch your word choice. Spend some time creating word lists that allow you to identify the depth of meaning or connotation of words.
Also, vary sentence length and type. By watching the structure of your sentences (simple, complex, etc.), you can create emotion and set the readers pace.
I really like the first person narrative and look forward to reading a re-write of this story.