Hi, 

In our opinion, we would suggest that you save the money for when it eventually needs to be cut down and replaced.

The Reliant product is a fungicide, and fungicides are only preventative, not curative. We don't see the need to apply that or how it would help with anything. 

The pyrethroid might stop future borer adults from laying eggs and creating additional borer damage, but it's not going to help with anything currently in the wood, if a borer is even involved.

We can't tell what caused the original damage, and it's hard to see clearly with the lighting in the photo.  It might have even been a normal growth crack that then got out of hand in terms of secondary issues like an infection or borer that took advantage of the weaker area of bark.

We are assuming the aeration is for the lack of root flare at the base of the tree where it meets the ground. The trunk should come straight down and flare at the base like the stem on a wine glass. When trees are planted too deeply or mulched too high (what is commonly referred to as a mulch volcano), it can cause girdling roots that wrap around the trunk and roots and deprive the canopy of nutrients. 

The root flare is likely the only thing we would suggest investing in fixing, so if you want to pay for aeration and root collar excavation, that might be sufficient.  Studies have shown that mycorrhizae applications are not beneficial (not necessarily harmful, but they also don't help and aren't needed since mycorrhizae are almost certainly already present and abundant enough). Plus, if the surrounding lawn is being fertilized at least once a year, the tree has sufficient nutrients, and too many synthetic nutrients (via fertilizer) can harm mycorrhizae, so that would make a deliberate mycorrhizae application even more pointless. 

Additionally, adding a mulch ring around the root zone after you expose the flare would help with any soil compaction in the immediate area from foot or mower traffic and add nutrients to the soil as the mulch decomposes. Monitoring the tree for watering needs through the fall until the ground freezes and in future growing seasons will help with additional stress from drought. 

Let us know if you have further questions. 

Emily