Sneezing is nothing to sneeze about (or is it?)

It is unlikely to be anything "like a cold." It can be anything from a foreign object to a tumor to allergies.

Since you are concerned about finances, have you considered Pet Insurance? What will happen if Louie develops a problem that is manageable but expensive to manage??

I have Healthy Paws® on my older, competition dog and Trupanion® on my kitten and my puppy. While none of them cover initial exams or annual exams or routine surgery (spay/neuter) they can be very helpful if your dog develops allergies or a multitude of other very expensive issues. They do not cover pre-existing conditions.

Most get more expensive as the pet ages (Trupanion is a little different that way and they have extra riders you can choose from). I reduced premium cost by raising the deductible and/or reducing the percentage coverage and then putting money in savings to cover those things.

Yes, you still have to pay the initial exam fee (in your case $69 and diagnostics) but if the issue "grows" into other expensive treatments it can make those treatments affordable vs. euthanizing the pet.

The issue here is if you do not have insurance.. or have it in place for a waiting period (every policy is different) and your dog is diagnosed with an insurable issue before the policy kicks in the condition will be considered "pre-existing." Pre-existing conditions are not covered.

Just a thought.

As an allergic human: allergies are miserable. If your vet has determined that the sneezing is most likely to do with allergies, then giving the antihistamines will at the very least confirm whether or not that diagnosis is correct (ie if the sneezing stops when the dog is medicated with an allergy med, then it's allergies). If the medication doesn't help, then that's a sign your vet might've missed something and there's something more serious going on, like a foreign object in the nasal cavity - that's valuable information to have! If the meds do work, you'll be improving your dog's quality of life. Untreated environmental allergies may not kill a dog, but they can make them feel unwell, which can in turn lead to undesireable changes in behavior (we've all gotten a bit grumpy when we're feeling sick before) and even a weakened immune system. No, allergies can't be cured, but they can and should be managed whenever possible.

If cost is an issue, call your vet and ask about alternatives. They may be able to set up solutions like sending the prescription to a human or third-party online pharmacy (often cheaper than buying directly from the vet), or help guide you in over-the-counter allergy medication that could help. Please do NOT try dosing your pup with human over-the-counter allergy medications without explicit instructions from your vet! Not all human medications are safe for dogs, and some require vastly different doses in dogs than what you'd give a human of the same weight. Some even have additives that are outright deadly toxic to dogs, like xylitol.