I have 3 groups of fields (each group consists of 2 fields) that I have to check against some condition. I don't check each field, but some combination, for example:

1. group priceEurBus, priceLocalBus
2. group priceEurAvio, priceLocalAvio
3. group priceEurSelf, priceLocalSelf

My example (formatted for legibility) — how can this be improved?

```
$rest .="
WHERE 
  (
    ((priceEurBus+(priceLocalBus / ".$ObrKursQuery.")) <= 400) 
    OR 
    ((priceEurAvio+(priceLocalAvio / ".$ObrKursQuery.")) <= 400) 
    OR
    ((priceEurSelf+(priceLocalSelf / ".$ObrKursQuery.")) <= 400)
  )
";

```

`$ObrKursQuery` is the value I use to convert local currency to Euro.